Impact of Distributed PV Generation on Relay Coordination and Power Quality

Wang²,

et al. 2020

Applied Sciences

The potential short-circuit current in active distribution network features time-variance with the increasing distributed generations. This feature makes the online estimation of fault level necessary. In this paper, a novel online estimation method is proposed to be implemented by either phasor measurement unit (PMU) or the measurements from protection relays. The equivalent circuit of the radial distribution network with distributed generators (DGs), e.g., wind turbines and photovoltaic cells, is derived with necessary simplifications. The natural disturbances downstream are used to evaluate the parameters of the equivalent circuit so that the potential fault level can be estimated in advance of the actual fault occurrence. A fuzzy logic identifier is presented to rank the confidence of the measurements incurred by the disturbance and to distinguish the qualified disturbance to launch the estimation. The mechanism based on multi-measurements and confidence indices was applied, to improve the accuracy. A typical distribution network in the United Kingdom (UK) with DGs was taken, as an example, to validate the proposed method under various load fluctuation. The results confirm the effectiveness of the proposed method, which is suitable for online estimation of short-circuit fault level in active distribution networks.

Section: Proposed Estimation Schemementioning

confidence: 99%

Online Estimation of Short-Circuit Fault Level in Active Distribution Network

Wang²,

et al. 2020

Applied Sciences

Period. Polytech. Elec. Eng. Comp. Sci.

“…• impact on OCR relay coordination for different scenarios [9], • fault current characteristics for the OCR performance under variant fault scenarios [10], • impact on short-circuit current and fault detection in PDS in the presence of DG sources [11],…”

Section: Introductionmentioning

confidence: 99%

Investigating the Performance of Non-standard Overcurrent Relay with Integration of Photovoltaic Distributed Generation in Power Distribution System

Zellagui,

Belbachir,

Amroune

et al. 2023

The electricity demand is increasing daily, so the generation power should be raised to fulfil that demand. Renewable distributed generation-based photovoltaic sources are one of the best solutions to satisfy the Power Distribution System (PDS) as long as the fossil resources are on the verge of extinction. At the same time, connecting the Photovoltaic Distributed Generation (PVDG) to the PDS may cause issues with the system's technical parameters, such as a protection system based on overcurrent relays, unless they are optimally allocated. In this context, this paper will be devoted to optimally allocating multiple PVDG units in the PDS using the Slime Mould Algorithm (SMA), meanwhile studying the impact of that optimal integration on the overcurrent protection system that will be represented and based on various chosen non-standard overcurrent relays (NS-OCRs) which many researchers develop, and trying to figure out and pick up the best type that provides improvement to the protection system including the minor impact on the coordination time interval. To achieve the maximum and best of the requested results, a multi-objective function was proposed to be minimized based on the sum of total active power loss, total voltage deviation, and total operating time of the relays.

Int Trans Electr Energ Syst

Anoff‐linealgorithm forfuse‐reclosercoordination in distribution networks with photovoltaic resources

Dadkhah

Fani

Heydarian‐Forushani³

et al. 2020

Summary Distributed energy resources (DERs) have a significant impact on the network's short‐circuit level and fault current direction, but it is almost impossible to precisely predict the presence of DERs in the distribution network. Hence, implementation of new settings for protection system based on a specific scenario for distributed generator, in terms of location and penetration level, is not a suitable solution. Utilization of adaptive protection and changing the overall design of protection system are very expensive and in many cases inapplicable. Consequently, it is crucial to propose a new method guaranteeing proper operation of protection system for any scenario of DERs based on the existing structure of distribution networks. This article proposes a new method evaluating the precise impact of photovoltaic resources on fault current profile and coordination of protective devices. Moreover, the proposed algorithm can update the settings of protective equipment, keeping protection coordination in distribution networks with variable penetration level of photovoltaic resources. Furthermore, the proposed method preserves fuse‐recloser coordination according to fuse saving theorem for transient faults.